An element P belongs to group 15. Its one of the allotrope is used in match box. It does not reacts with dil.H2SO4. It forms two oxides X and Y which turn blue litmus red. Identify P, X and Y. Write the reaction of P to form X and Y.

Q. Question 32
A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water, it forms a solution which turns red litmus blue. Identify X and also write the chemical reactions involved.

Q. If a substance X reacts with air to form an oxide Y that turns moist blue litmus red, then X is .

Q. An element X that react with oxygen and form an oxide $X_{2}O$. This oxide dissolves in water and turns red litmus blue. Element $X$ is :

Q. A substance $X$ which is an oxide of a group element is used intensively in the cement industry. This element is also present in bones. On treatment with water, it forms a solution which turns red litmus blue. What is $X$?

Q. A highly reactive substance X is stored safely under water. It readily reacts with oxygen to give a compound Y which dissolves in water. The aqueous solution of Y changes blue litmus solution to red. Identify X and Y.